An evaluation method and device for favorable zones based on dynamic evolution of fault properties and effects

Abstract

The present application belongs to the technical field of oil and gas bearing basin favorable exploration zone research, and particularly relates to a method and device for evaluating favorable zones based on dynamic evolution of fault properties and effects. The evaluation method comprises stress field characteristic analysis, structural profile characteristic analysis, basin structure analysis, fault system and structural pattern characteristic analysis, favorable zone selection and exploration target selection steps. The present application considers that under the superimposed action of multiple phases, different directions and different properties of stress, the properties of faults (reverse faults, normal faults, strike-slip faults) also undergo alternating evolution of waxing and waning, and the effects of different properties of faults on oil and gas transport, reservoir fracture structure, oil and gas sealing and preservation also differ. The present application analyzes the property evolution of faults and their control effect on oil and gas reservoirs from the perspective of spatiotemporal dynamic evolution, and predicts favorable exploration zones, thereby indicating the direction for fine exploration.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of favorable exploration zone research of oil and gas bearing basin, and particularly relates to a favorable zone evaluation method and device based on dynamic evolution of fault properties and effects. BACKGROUND

[0002] Most basins have superimposition or combination of compression, tension and strike-slip deformation in tectonic evolution, and the key is which stress is dominant in different periods or different positions in plane. The tectonic evolution is often the final result of superimposition of multi-period, different direction and different property stresses. The paleo-tectonic stress is the direct cause of various paleo-tectonic phenomena, and various forms of geological traces left in the deformed strata are the direct performance of the paleo-tectonic stress. The paleo-tectonic stress research mainly determines the stress state of each point, and then studies the distribution law of the structure in a certain area range from point to plane. There are many methods for paleo-tectonic stress research, which can use various structural traces in the field, such as conjugate joints, fault rub marks, folds and cleavages, to judge the paleo-tectonic stress direction and restore the paleo-tectonic stress field. The tectonic stress is the main factor for the formation and multiple activities of faults, and it is of great significance to understand the tectonic movement and its action form in the target area to understand the action mode and evolution form of the tectonic stress.

[0003] Fault activity research and comparison is an important content of tectonic evolution research. The quantitative methods for studying the fault activity intensity include growth index method, paleo-drop analysis method, activity rate method and paleo-sliding distance method, each method has specific application conditions and advantages and disadvantages. Many scholars have carried out a lot of research on the boundary fault of continental fault sag basin, and proposed a segmented growth model of boundary fault. The formation of boundary fault controlling sag experiences isolated segmentation, soft connection and hard connection, and finally forms a unified boundary fault controlling sag. The segmented growth process of boundary fault controlling sag controls the migration of sag and the distribution of sedimentary system and sand body, and further controls the distribution range of effective hydrocarbon source rock in different periods. The paleo-uplift formed in the composite process of each secondary fault sag is often a favorable position for oil and gas accumulation. Since the basement of the basin has more or less some pre-existing structures, whether the pre-existing structures can be active and the sequence of activity depends on the orientation and mechanical properties of the pre-existing structure surface. Due to the change of principal stress direction, the activity of pre-existing structure may change fundamentally, which may lead to the weakening or stop of the activity of the boundary. With the change of stress system, the pre-existing fault formed in the previous period becomes the pre-existing fault in the current period, and the boundary fault is often composed of "pre-existing structure reactivation fault" combination.

[0004] The different properties of the derived faults of the controlling-basin or controlling-depression faults in different tectonic stress positions affect the trap types and the fault sealing capacity. The differences in the fault activity time and intensity affect the oil and gas migration and preservation, and further affect the oil and gas enrichment horizon and degree. The faults communicating with the oil source have large fault throw, strong activity and long activity time, and the oil and gas is relatively more enriched in the tectonic area. The oil source fault is the main channel for the vertical migration of oil and gas, and the transport capacity is restricted by the activity of the oil source fault. Only the fault which is active in the key period of reservoir formation, communicates with the effective source rock and reservoir, and has the top sealing capacity, can provide an advantageous transport channel for the migration of oil and gas, so that a large amount of oil and gas discharged from the mature source rock can be accumulated in the reservoir. The oil and gas is not distributed around the whole oil source fault, but is concentrated in the positions where the transform structures are developed, such as the turning point of the fault strike, the intersection of the faults and the end of the fault. The favorable positions of the oil source fault for oil and gas enrichment are mainly affected by three factors: the convex ridge with relatively strong activity, the relatively developed sand body position and the position where the micro-amplitude nose structure associated with the fault is developed. The accumulation position of the oil and gas controlled by the oil source fault, the lateral sealing capacity of the fault, the fault activity intensity after the reservoir formation and the preservation degree of the early accumulated oil and gas can be comprehensively considered to establish the standard for the selection of the favorable target.

[0005] Jia Nan et al. (Geological Science, April 2015) studied the neogene tectonic reformation and evolution of Liaodongwan Depression, analyzed the neogene tectonic reformation of Liaodongwan Depression, the neogene activity characteristics and forms of Tanlu fault zone and the neogene evolution of Dongwan Depression, but did not establish the relationship between different structures and the accumulation or migration of oil and gas, and how to carry out the next step of favorable zone evaluation and prediction is unknown. SUMMARY

[0006] The purpose of the present application is to provide an evaluation method of favorable zones based on the dynamic evolution of fault properties and effects, which can effectively predict the favorable exploration zones and provide guidance for well deployment.

[0007] The second purpose of the present application is to provide an evaluation device corresponding to the above-mentioned method.

[0008] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0009] An evaluation method of favorable zones based on the dynamic evolution of fault properties and effects, comprising the following steps:

[0010] (1) From the regional tectonic position of the study area, the regional tectonic evolution history is analyzed, and the stress field characteristics of the study area in different periods and under different stress directions are studied;

[0011] (2) The structure of the study area is analyzed, the geological interpretation map of the seismic profile of the study area is obtained, and the geological profile is converted through the velocity formula to determine the present tectonic profile characteristics;

[0012] (3) According to the seismic profile interpretation scheme of the research area, the structural units in different periods of the research area are divided, the planar distribution characteristics of the present faults, depressions and protrusions are determined, and the basin structure analysis is carried out;

[0013] (4) According to the seismic profile interpretation scheme of the research area, the fault system and structural style characteristics in different periods of the research area are analyzed;

[0014] (5) The structural evolution profile of the research area is restored, the space-time evolution characteristics of the fault system and the structural style are analyzed, the weakly reformed area is selected as the favorable area of the original oil and gas reservoir according to the space-time evolution characteristics of the oil and gas accumulation or migration, and the weakly reformed area is finely dissected;

[0015] (6) The depth and range of the high thermal evolution area of the source rock in the research area are determined, the structural high position strike-slip fault sealing and the low position fault lateral docking type in the source are selected as the favorable exploration target, and the well site is deployed.

[0016] The application considers that under the superposition of multi-period, different directions and different nature stresses, the nature of the fault (reverse fault, normal fault, strike-slip fault) also alternately evolves, and the different nature faults have different effects on the oil and gas transportation, the structural of the reservoir fracture, the sealing and preservation of the oil and gas. From the perspective of space-time dynamic evolution, the nature evolution of the fault and the control effect on the oil and gas reservoir are analyzed, and the favorable exploration area is predicted, which points out the direction for fine exploration.

[0017] Preferably, in step (5), the analysis of the space-time evolution characteristics of the fault system and the structural style includes analysis of the inheritance and migration of the depression and protrusion; the development of the depression inheritance develops high-quality source rocks; the development of the protrusion inheritance forms a favorable migration direction of oil and gas migration.

[0018] Preferably, in step (5), the analysis of the space-time evolution characteristics of the fault system and the structural style includes analysis of the fault activity strength; the small fault activity intensity is weakly reformed, and is easy to form in-situ accumulation; the large fault activity intensity is strongly reformed, and is easy to form out-of-source accumulation.

[0019] Further preferably, in step (5), the weakly reformed area has the development of the depression inheritance and the complete structural trap, and forms the in-situ accumulation.

[0020] Preferably, in step (6), the source rock in the high thermal evolution area has a burial depth of 4500 meters and a gas generation intensity greater than 20 billion cubic meters / km 21.5%<Ro<2.5%. Ro is the symbol of vitrinite reflectance. Vitrinite reflectance is the most important index of maturity of organic matter of hydrocarbon source rock, and is used to calibrate the thermal evolution of organic matter from early diagenesis to deep metamorphic stage. The deeper the thermal metamorphism of organic matter, the greater the vitrinite reflectance.

[0021] Preferably, in step (5), the tectonic evolution profile restoration is performed according to the principle of multi-stress superposition space-time evolution and balanced profile.

[0022] An evaluation device for favorable zones under dynamic evolution of fault properties and effects comprises the following functional modules:

[0023] A stress field characteristic analysis module: based on the regional tectonic position of the study area, the regional tectonic evolution history is analyzed, and the stress field characteristics of the study area in different periods and different stress directions are studied;

[0024] A tectonic profile characteristic analysis module: the study area is analyzed, the geological interpretation map of the seismic profile of the study area is obtained, and the geological profile is converted through the velocity formula to determine the existing tectonic profile characteristics;

[0025] A basin structure analysis module: based on the seismic profile interpretation scheme of the study area, the tectonic unit division of the study area in different periods is performed, the planar distribution characteristics of the existing faults, depressions and protrusions are determined, and the basin structure analysis is performed;

[0026] A fault system and tectonic style characteristic analysis module: based on the seismic profile interpretation scheme of the study area, the fault system and tectonic style characteristics of the study area in different periods are analyzed;

[0027] A favorable zone selection module: the tectonic evolution profile of the study area is restored, the space-time evolution characteristics of the fault system and tectonic style are analyzed, the space-time evolution characteristics are used to judge the oil and gas accumulation or migration, the weakly reformed area is selected as the favorable zone of the original oil and gas reservoir, and the weakly reformed area is finely dissected;

[0028] An exploration target selection module: the depth and range of the source rock in the high thermal evolution zone of the study area are determined, the tectonic high position strike-slip fault sealing and the low position fault lateral docking type in the source are selected as the favorable exploration target, and the well site is deployed.

[0029] The evaluation device for favorable zones under dynamic evolution of fault properties and effects of the application uses the above module group functional module architecture, so that the evaluation result can be quickly and effectively obtained.

[0030] Preferably, in the favorable zone selection module, the analysis of the time-space evolution characteristics of the fault system and the structural pattern comprises analysis of the inheritance and migration of the depression and the uplift; if the depression inheritance develops, high-quality hydrocarbon source rocks develop; if the uplift inheritance develops, favorable migration directions of oil and gas migration are formed.

[0031] Preferably, in the favorable zone selection module, the analysis of the time-space evolution characteristics of the fault system and the structural pattern comprises analysis of the fault activity strength; if the fault activity strength is small, the reconstruction is weak, and the source-in accumulation is easy; if the fault activity strength is large, the reconstruction is strong, and the source-out accumulation is easy.

[0032] Further preferably, in the favorable zone selection module, the weak reconstruction area has the depression inheritance development and the complete structural trap, and forms the source-in accumulation. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a flow chart of a favorable zone evaluation method based on the dynamic evolution of the fault properties and the role for the present application;

[0034] Figure 2 It is a regional structural position map of a research area in the embodiment of the present application (taking the Dongpu depression as an example);

[0035] Figure 3 It is a regional seismic time section interpretation scheme in the embodiment of the present application (taking Dongpu depression large section 8 as an example);

[0036] Figure 4 It is a regional depth geological section interpretation scheme in the embodiment of the present application (taking Dongpu depression large section 8 as an example);

[0037] Figure 5 It is a structural unit division map in the embodiment of the present application (taking the bottom surface of the 1-4 sand group of the middle sub-section of the third member of the Shahejie Formation in the Dongpu depression as an example);

[0038] Figure 6 It is a fault system distribution map in different periods in the embodiment of the present application (taking the Indosinian-Yanshanian period in the Dongpu depression as an example);

[0039] Figure 7 It is a fault system distribution map in different periods in the embodiment of the present application (taking the Himalayan period in the Dongpu depression as an example);

[0040] Figure 8 It is a structural evolution section restoration map based on the principle of multi-stress superposition time-space evolution and balanced section in the embodiment of the present application (taking Dongpu depression large section 8 as an example);

[0041] Figure 9 It is a favorable trap distribution map of a weak reconstruction area in the embodiment of the present application (taking the Wenliu structural belt in the Dongpu depression as an example);

[0042] Figure 10 This is a map showing the deployment of favorable exploration target well locations under high-temperature evolution conditions in a weakly modified zone, as illustrated in this embodiment of the invention (taking the Wenliu structural belt in the Dongpu Depression as an example). Detailed Implementation

[0043] The implementation process of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Example 1: Evaluation Method of Favorable Zones Based on Fault Properties and Dynamic Evolution

[0045] The Bohai Bay Basin is located in the central region of the North China Craton, bounded by the Taihang Mountains, the Yanshan Fold Belt, the Jiaoliao Uplift, and the Luxi Uplift. Four regional strike-slip fault zones are developed within the basin, with varying degrees of development at different locations, resulting in significant differences in the development of various depressions. Based on the stress field environment of each depression, the Bohai Bay Basin can be divided into northern and southern shear tectonic zones and a central transform-extensional tectonic zone. The Dongpu Depression, part of the Linqing Depression, is located at the southernmost end of the Bohai Bay Basin. The depression is narrower in the north and wider in the south, with an area of ​​approximately 5300 km². 2 .

[0046] The formation of the Bohai Bay Basin exhibits evolutionary characteristics of Indosinian-Yanshanian reverse faulting, Paleogene normal faulting, and late-stage strike-slip stabilization. Fault activity plays a crucial role in controlling hydrocarbon accumulation. Previous studies have extensively investigated the Paleogene basin structure, extensional fault system, and tectonic styles of the Dongpu Depression, but research on the dynamic evolution of fault properties and functions under multiple tectonic stresses across different generations is limited. This study, starting from the regional tectonic background of the Bohai Bay Basin, investigates the formation and evolution of the Dongpu Depression across different generations, meticulously dissecting tectonic styles and zoning characteristics under varying stresses. It evaluates favorable zones under the dynamic evolution of fault properties and functions, and, combined with the hydrocarbon enrichment conditions under the high-temperature evolution of coal-bearing source rocks, provides direction for selecting exploration areas and zones in the Upper Paleozoic of the Dongpu Depression.

[0047] A specific embodiment of the evaluation method for favorable zones based on the dynamic evolution of fault properties and effects of the present invention is shown in the flowchart below. Figure 1 As shown, the following steps are taken:

[0048] (1) From the regional tectonic location of the study area ( Figure 2 To conduct regional tectonic evolution history analysis and study the stress field characteristics of the study area under different periods and stress directions.

[0049] The North China Craton is located at the center of the world's three major tectonic domains and has been surrounded by orogenic belts of different periods for a long time. Through the successive amalgamation, simultaneous union and later rifting of multiple blocks, it has formed a complex and diverse tectonic pattern, which is divided into the eastern block, the western block and the central north-south tectonic belt. The eastern block is severely damaged. The Bohai Bay Basin is a Mesozoic-Cenozoic basin on the eastern block and is located in the central area of ​​the North China Craton's destruction.

[0050] Since the Mesozoic Era, the Bohai Bay Basin has undergone four tectonic stages of changes in regional stress, basin structure, and nature: Late Triassic, near-north-south compression, eastward stripping and westward subsidence, compressional thrust; Early-Middle Jurassic, tectonic transformation to near-east-west compression, truncation and filling of depressions, and overburden deposition; Late Jurassic-Early Cretaceous, reverse faulting and depression, northwest-southeast extension, differential faulting and depression, with distinct zonation; Late Cretaceous, northwest-southeast compression and uplift, overall uplift, compressional thrust.

[0051] During the Cenozoic era, the Bohai Bay Basin was subjected to two major tectonic stress fields: the subduction of the Pacific Plate and the collision and compression between the Indian and Eurasian Plates. Due to the long-range effects of the Indian Plate subduction, coupled with the retreating subduction of the Pacific Plate, the basin's extensional direction was NW, with the primary driving force being the long-range effects of the collision between the Indian and Eurasian Plates. The change in the Pacific Plate subduction direction from NNW to NWW reduced the left-lateral strike-slip shear stress and increased the right-lateral shear stress in the basin, forming three right-lateral strike-slip shear zones trending NNE or NE in the Bohai Bay Basin. The Dongpu Depression, located at the southernmost tip of the Bohai Bay Basin, possesses a multi-stage, multi-direction, and multi-nature tectonic stress field background.

[0052] (2) Based on the seismic profiles and drilling and logging data of the study area, structural analysis was performed to obtain the geological interpretation map of the seismic profiles of the study area. Figure 3 ), and converted into geological profiles through the velocity formula ( Figure 4 ), to determine the existing structural profile features.

[0053] Taking the Dongpu Depression section 8 as an example, from east to west, it passes through the Lanliao Fault Zone, Wendong Fault Zone, Wenxi Fault Zone, Shijiaji Fault Zone, and Mazhai Fault Zone. Vertically, it develops a basement thrust fault system and a Cenozoic extensional-strike-slip fault system, which control the distribution of Paleozoic, Mesozoic Triassic, Paleogene, Neogene, and Quaternary systems.

[0054] In the western slope zone and the Lanliao fault zone, the thrust faults developed in the Paleogene increased in displacement, forming relatively large-amplitude anticlines. The thrust faults pinched out upwards and disappeared at the bottom of the Sha-4 Formation. In the central uplift zone, the thrust fault displacement of the Paleogene decreased, and the amplitude of the formed anticlines decreased. The Paleozoic strata were distributed approximately horizontally in the central uplift zone.

[0055] The Paleogene basin in the central region is generally thicker in the east and thinner in the west. The western slope, from west to east, intersects Ng with CP, T, S4, and S3 in that order.下 S1, Ed unconformable contact. The east-dipping Mazhai fault, Shijiaji fault, Wendong fault, etc. intersect with the west-dipping Lanliao fault, Weixi fault, etc. to form multiple grabens or half-grabens. Overall, the high uplift and deep depression characteristics are obvious, and the Lanliao fault, which controls the basin, is in the form of a spade with steep upper and gentle lower. The hanging wall of the Lanliao fault zone develops, from bottom to top, the Carboniferous-Permian, the Mesozoic Triassic, Es4, Es3L, Es3M, Es3U, Es2L, Es2U, Es1, Dongying, Guantao, and Minghuazhen formations, and the top of the Triassic and the bottom of the Cenozoic Es4 are angular unconformity and parallel unconformity.

[0056] The Pucheng fault has disappeared on this profile, and two reverse adjustment faults can be seen on the hanging wall of the Lanliao fault. The Wendong fault is gently inclined upward and steeply inclined downward, nearly vertical, and pinches out in the Guantao Formation upward and the Carboniferous-Permian downward, and the hanging wall develops multiple reverse adjustment faults. The Wenxi fault pinches out in the Guantao Formation downward and intersects with the east-dipping Shijiaji fault downward. The Changyuan fault is in the form of a spade with steep upper and gentle lower, pinches out in the Minghuazhen Formation upward, and intersects with the detachment fault of the basement downward.

[0057] (3) According to the interpretation scheme of the seismic profile in the study area, the tectonic units in different periods are divided ( Figure 5 ), the planar distribution characteristics of the existing faults, depressions and uplifts are determined, and the basin structure analysis is carried out.

[0058] The pre-Paleogene basement of the Dongpu Sag formed an east-west thrust belt and a transfer fault in the Indosinian period, and under the cutting of the northeast-trending faults in the Paleogene, complex tectonic units were formed. According to the industry standard for tectonic unit division, major faults, isobaths, and stratigraphic pinchout lines, combined with the latest results of tectonic map and tectonic outline map, the tectonic units of the Dongpu Sag are redefined. The Dongpu Sag is divided into the Lanliao fault step zone, the eastern sub-sag zone, the central low uplift, the western sub-sag zone, and the western slope zone. Due to the rapid conversion of tectonic belts in different periods of the Dongpu Sag, 43 one- and two-level faults, 35 positive structures, and 12 negative structures are formed after redefinition.

[0059] (4) According to the interpretation scheme of the seismic profile in the study area, the characteristics of the fault system and the tectonic style in different periods are analyzed ( Figure 6 、 Figure 7 ).

[0060] Fault system refers to various combinations of faults of different properties formed in a certain regional tectonic stress field, their spatial arrangement, mutual intersection relationship, and the mechanical mechanism and displacement characteristics of the faults. Fault system includes thrust fault system, tensional fault system, and strike-slip fault system, which can exist in one form or two or three forms.

[0061] ​​The structural style refers to the combination of structural deformation generated by the same tectonic movement and in the same stress environment. The structural style can be divided into thrust structural style, tensional structural style and strike-slip structural style according to the stress property. Each structural style under each tectonic stress can be further divided into many types.

[0062] The Dongpu Sag was subjected to strong near NS compression during the Indosinian period, forming a series of near EW thrust fault systems and large-scale anticlines ( Figure 6 ) and a north-south zonation pattern. The area north of the Guan 2-Guancheng thrust fault is the north zone, the area between the Xichengji-Mengju thrust fault and the Guan 2-Guancheng thrust fault is the middle zone, and the area south of the Xichengji-Mengju thrust fault is the south zone. The north zone is controlled by the boundary thrust fault and is a large anticline structure. The middle zone is a syncline structure as a whole, with the Qianliyuan area as the center of the syncline structure. The south zone is characterized by a large number of thrust faults and a high overall uplift, and is composed of multiple anticline structures. During the Yanshanian period, the Dongpu Sag was subjected to weak NW-SE compression, forming NE-trending thrust fault systems and anticlines, and still inheriting the north-south zonation pattern. The thrust faults are small in amplitude and high in density, forming a series of uplift structures and thrust fault steps.

[0063] The Dongpu Sag was subjected to strong near NS compression during the Indosinian period, forming a series of near EW thrust fault systems and large-scale anticlines ( Figure 6 ) and a north-south zonation pattern. The north zone is controlled by the boundary thrust fault and is a large anticline structure. The middle zone is a syncline structure as a whole, with the Qianliyuan area as the center of the syncline structure. The south zone is characterized by a large number of thrust faults and a high overall uplift, and is composed of multiple anticline structures. During the Yanshanian period, the Dongpu Sag was subjected to weak NW-SE compression, forming NE-trending thrust fault systems and anticlines, and still inheriting the north-south zonation pattern. The thrust faults are small in amplitude and high in density, forming a series of uplift structures and thrust fault steps. Figure 7 (5) Structural evolution profile restoration is performed according to the principle of multi-stress superimposition and space-time evolution and balanced profile, the space-time evolution characteristics of the fault system and the structural style are analyzed, the weakly reformed area is selected as the favorable zone of the primary oil and gas reservoir, and the weakly reformed area is finely dissected.

[0064] Figure 8 (5) Structural evolution profile restoration is performed according to the principle of multi-stress superimposition and space-time evolution and balanced profile, the space-time evolution characteristics of the fault system and the structural style are analyzed, the weakly reformed area is selected as the favorable zone of the primary oil and gas reservoir, and the weakly reformed area is finely dissected.

[0065] ​The evolution of the fault system with different stress properties and directions in different stages results in the obvious zonation of the sag. The Dongpu Sag as a whole has the following characteristics of the tectonic evolution: the Indosinian-Yanshanian extrusion zonation, the Paleogene extensional zone, the sag-controlled depression during the deposition of the fourth and third members of the Shahejie Formation, and the strike-slip block formation during the deposition of the second member of the Shahejie Formation.

[0066] The differences in the properties, occurrence and activity intensity of the faults in different evolution stages of each zone result in the diversity of the basin structure, the formation of different structural units, and the inheritance and migration of the planar distribution of the faults, sags and uplifts in different stages. The inheritance of the sags and the development of the high-quality source rocks, the inheritance of the uplifts and the favorable migration direction of the oil and gas, the weak activity intensity of the faults and the easy in-reservoir accumulation, the strong activity intensity of the faults and the easy out-of-reservoir accumulation, and the segmentation and property changes of the fault evolution in different stages have important guiding significance for the oil and gas exploration.

[0067] The Dongpu Sag is a large-scale anticline in the north and south zones, a large-scale syncline in the middle zone, and a small-scale anticline in some parts. The Indosinian extrusion is large in amplitude and the north and south zones are obviously divided. The Yanshanian extrusion is weak, the fourth and third members of the Shahejie Formation are strongly extended, the second member of the Shahejie Formation and the following periods are right-lateral strike-slip and weak extension. The late period of the north zone is strongly extended and the domino-type fault terrace is strongly reformed. The middle zone is high and low, the anticline shape, and the strike-slip sealing effect is obvious. The south zone is strongly reformed and the half-anticline shape. The present study considers that the middle zone is a weakly reformed zone, the sags are inherited, and the high-quality source rocks are developed, which is a favorable in-reservoir exploration zone of the Paleozoic. The Weicheng-Wenliu area is selected as the key zone for the well deployment.

[0068] The weakly reformed zone of the basin is divided by the statistics and analysis of the indicators representing the tectonic activity intensity, such as the fault throw surface density, the formation curvature and the formation thickness change rate. The weakly reformed zone and the strongly reformed zone are a relative concept for a certain basin. The weakly reformed zone is mainly distributed in the sag and slope areas, the fault activity intensity is relatively small or not developed, and the oil and gas accumulation is mainly controlled by the source rocks and the migration system.

[0069] The fine dissection includes the following: (1) In the seismic work area, the seismic profile lines are interpreted with high density. The interval of the seismic profile lines in the basin or depression is 10*10 (i.e. one main line and one connecting line are selected with an interval of 100 meters), while the interval of the seismic profile lines in the favorable zone is 1*1 (i.e. one main line and one connecting line are selected with an interval of 10 meters). (2) The level of the fault is studied more finely, which can reach the fifth level of controlling the micro-amplitude structure. In the basin or depression, the level of the fault is only required to reach the third level of the fault (the first level of the fault controls the basin, the second level of the fault controls the depression, the third level of the fault controls the depression or the structural belt, the fourth level of the fault controls the trap, and the fifth level of the fault controls the micro-amplitude structure). (3) The matching relationship between the evolution of the different levels of the fault and the oil and gas accumulation is studied more finely. According to the fault activity time and the plane segmentation characteristics, the fault is further classified into the source-controlling fault and the non-source-controlling fault, which further clarifies the relationship between the different faults and the oil and gas transportation or sealing, and predicts the favorable exploration target.

[0070] (6) The depth and range of the source rock in the high thermal evolution zone in the study area are determined. The source-in structural high position strike-slip fault sealing and low position fault lateral docking type are preferred as the favorable exploration target.

[0071] In this step, the source-in accumulation exploration target optimization is carried out by comprehensively considering the source rock in the high thermal evolution zone, the sealing effect of the fault on the oil and gas accumulation in different periods, and the integrity of the structural trap in the weakly reformed area.

[0072] The fine dissection is carried out on the Weicheng-Wenliu area in the Dongpu depression. On the east side (the upthrown side) of the main strike-slip fault with the characteristics of the first reverse, then positive and then strike-slip in the central low uplift, three large Upper Paleozoic structural traps are developed. Figure 9 In combination with the fact that the source rock is buried at a depth of 4500 meters, the gas generation intensity is greater than 20 billion cubic meters / km2, and 1.5 < Ro < 2.5 is the high thermal evolution zone for the coal-derived gas in the Dongpu depression, the three traps are evaluated and optimized. The reservoir at the top of the Carboniferous-Permian in the north is buried at a depth of about 3400 meters. The source rock is located outside the high thermal evolution zone, and the gas source is not good. The reservoir at the top of the Carboniferous-Permian in the middle is buried at a depth of about 3700 meters. The coal measure source rock is partially located in the high thermal evolution zone, the gas source is insufficient, the small faults are reformed into multiple fault blocks, and the preservation is not good. The reservoir at the top of the Carboniferous-Permian in the south is buried at a depth of about 3900 meters. The source rock is in the high thermal evolution zone, the gas source is sufficient, the structure is simple and complete, and the preservation condition is good, which is a favorable trap for oil and gas exploration. According to the latest structural dissection scheme and the oil and gas accumulation mechanism in the high thermal evolution zone, the source-in structural high position strike-slip fault sealing and low position fault lateral docking type are preferred as the favorable exploration target. One Paleozoic risk well is designed and deployed in the Weicheng-Wenliu structural belt Figure 10 , which will open up a new situation in the field of Paleozoic oil and gas exploration and has important strategic guiding significance for increasing reserves and production in the old Dongpu area.

[0073] Example 2: Evaluation device for favorable zones based on the dynamic evolution of fault properties and effects

[0074] The evaluation device for favorable zones based on fault properties and dynamic evolution in this embodiment corresponds to the implementation process of the method in Embodiment 1. It includes a stress field characteristic analysis module, a structural profile characteristic analysis module, a basin structure analysis module, a fault system and structural style characteristic analysis module, a favorable zone selection module, and an exploration target selection module, which correspond to the corresponding steps of the method in Embodiment 1. The above modules are used to form a functional module framework, thereby realizing the exploration and evaluation of favorable zones of Paleozoic oil and gas reservoirs.

Claims

1. A method for evaluating a favorable zone based on dynamic evolution of fault properties and effects, characterized in that, The method comprises the following steps: (1) analyzing the regional tectonic evolution history from the regional tectonic position of the study area, and researching the stress field characteristics of the study area under different stress directions in different periods; (2) analyzing the structure of the study area, obtaining a geological interpretation diagram of a seismic profile of the study area, and converting the geological interpretation diagram into a geological profile through a velocity formula to determine the existing tectonic profile characteristics; (3) dividing the tectonic units of the study area in different periods according to the interpretation scheme of the seismic profile of the study area, determining the planar distribution characteristics of the existing faults, depressions and protrusions, and analyzing the basin structure; (4) analyzing the characteristics of the fault system and the tectonic style in different periods of the study area according to the interpretation scheme of the seismic profile of the study area; (5) restoring the tectonic evolution profile of the study area, analyzing the time-space evolution characteristics of the fault system and the tectonic style, judging the oil and gas accumulation or migration according to the time-space evolution characteristics, selecting a weakly reformed area as a favorable area of a primary oil and gas reservoir, and finely dissecting the weakly reformed area; (6) determining the depth and range of the source rock in the high thermal evolution area of the study area, selecting a tectonic high position strike-slip fault sealing and a low position fault lateral docking type in the source as a favorable exploration target, and deploying a well site.

2. The method for evaluating the favorable zone based on the dynamic evolution of the fault properties and effects according to claim 1, characterized in that, In step (5), the analysis of the time-space evolution characteristics of the fault system and the tectonic style comprises analysis of the inheritance and migration of the depression and the protrusion; the development of the inheritance of the depression develops high-quality source rocks; the development of the inheritance of the protrusion forms a favorable migration direction of oil and gas migration.

3. The method for evaluating the favorable zone based on the dynamic evolution of the fault properties and effects according to claim 1, characterized in that, In step (5), the analysis of the time-space evolution characteristics of the fault system and the tectonic style comprises analysis of the fault activity strength; the small fault activity strength is weakly reformed and easy to accumulate in the source; the large fault activity strength is strongly reformed and easy to accumulate outside the source.

4. The method for evaluating a favorable zone based on dynamic evolution of fault properties and effects according to any one of claims 1 to 3, characterized in that, In step (5), the weakly reformed area has the development of the inheritance of the depression and the integrity of the structural trap, and forms the accumulation in the source.

5. The method for evaluating the favorable zone based on the dynamic evolution of the fault properties and effects according to claim 1, characterized in that, In step (6), the hydrocarbon source rock in the high thermal evolution zone has a burial depth of 4500 meters and a gas generation intensity greater than 2 billion cubic meters per kilometer 2 1.5% < Ro < 2.5%.

6. The method for evaluating favorable zones based on dynamic evolution of fault properties and behavior according to any one of claims 1, 2, 3, 5, characterized in that, In step (5), the tectonic evolution profile is restored according to the principle of multi-stress superposition time-space evolution and balanced profile.

7. An apparatus for evaluating a favorable zone based on dynamic evolution of fault properties and effects, characterized in that, The method comprises the following functional modules: a stress field characteristic analysis module for analyzing the regional tectonic evolution history from the regional tectonic position of the study area, and researching the stress field characteristics of the study area under different stress directions in different periods; a tectonic profile characteristic analysis module for analyzing the structure of the study area, obtaining a geological interpretation diagram of a seismic profile of the study area, and converting the geological interpretation diagram into a geological profile through a velocity formula to determine the existing tectonic profile characteristics; a basin structure analysis module for dividing the tectonic units of the study area in different periods according to the interpretation scheme of the seismic profile of the study area, determining the planar distribution characteristics of the existing faults, depressions and protrusions, and analyzing the basin structure; a fault system and tectonic style characteristic analysis module for analyzing the characteristics of the fault system and the tectonic style in different periods of the study area according to the interpretation scheme of the seismic profile of the study area; a favorable area selection module for restoring the tectonic evolution profile of the study area, analyzing the time-space evolution characteristics of the fault system and the tectonic style, judging the oil and gas accumulation or migration according to the time-space evolution characteristics, selecting a weakly reformed area as a favorable area of a primary oil and gas reservoir, and finely dissecting the weakly reformed area; The exploration target selection module determines the depth and range of the hydrocarbon source rock in the high thermal evolution zone of the study area, selects the tectonic high position strike-slip fault sealing and low position fault lateral docking type in the source as the favorable exploration target, and deploys the well site.

8. The apparatus for evaluating a favorable zone based on dynamic evolution of fault properties and effects according to claim 7, wherein, In the favorable zone selection module, the analysis of the space-time evolution characteristics of the fault system and the structural style includes analysis of the inheritance and migration of the depression and the uplift; the development of the inheritance of the depression develops high-quality hydrocarbon source rocks; the development of the inheritance of the uplift forms a favorable migration direction of oil and gas migration.

9. The apparatus for evaluating a favorable zone based on dynamic evolution of fault properties and effects according to claim 7, wherein, In the favorable zone selection module, the analysis of the space-time evolution characteristics of the fault system and the structural style includes analysis of the fault activity strength, and the weak fault activity intensity is weakly reformed and easy to form in-source accumulation; the fault activity intensity is strong and easy to form out-of-source accumulation.

10. Apparatus for evaluating, on the basis of the dynamic evolution of the properties and effects of the fault, the zones of interest according to any one of claims 7 to 9, characterized in that, In the favorable zone selection module, the weak reformation area has the development of the inheritance of the depression and the integrity of the structural trap, forming in-source accumulation.

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